Supercharger problem or customer service failure? Join the Club

Hi Bob,
I do have a Sebring supercharger running on my 96 1.6l Miata, here in Germany. It is an old version and so I want to install a Check valve into the idle speed control line to prevent backflow and loss of boost. This line is set between the dummy throttle body before the intake system and the pre-supercharger air line. In the Miata Performance Handbook of N. Garrett III there is a picture of this so called STANDARD AV-23 check valve but no part no. from the NAP store or another supplier.

So, where can I buy/order this check valve and which part number does it carry?

Michael, Germany

Michael, I'd be chatting with the makers of the kit or whoever you bought it from. Inasmuch as Mazda has to jump through hoops to do all the durability and environmental testing of a car as well as provide customer support, any third-party worth healing with would be able to at least match what the car's manufacturer does in these areas. So if whoever built or sold you the supercharger kit should be able to provide you with at least one "STANDARD AV-23 check valve". Perhaps hundreds more. If not, well, you may have dealt with a less than honest supplier and/or manufacturer. Then again, you could contact Norman Garrett III for advice, as you point out the item was mentioned in the Miata Performance Handbook he published. As I recall, in addition to his numerous duties at the Miata Club of America, Norman was selling somebody's supercharger at one point in time. Yes, he might be just the guy to touch bases with on this.

As you are aware, Mazda does not approve or warrant supercharger installations. One of the reasons - among many - is precisely because of the lack of customer support you're now experiencing.

bwob

Aged and Treacherous in Kansas City

I'd just like to point out that, although we live in the same greater Kansas City area, I do not now, nor have I ever, had any association with Thomas Fee of Lenexa, who posted in the December "Ask Bob" section.  

Dick Carlson, Jack London's, Carmel

Inasmuch as Mr. Carlson's age and treachery are well documented by numerous Congressional sub-committees and by the United Nations Security Council, his comments are posted without comment. However someone named PJ secretly revealed to Miata.net that Dick changed all his Miata's fuses to see if it really would eliminate tappet noise...

bwob

Does my Miata really need a CPU?

I have a question about, getting either a supercharger or a ignition system, the question being, will the pistons handle this for a long time? do they have a bad case of blowing out? and just how far (on occasion- not often) can I safely red line my tach.? And finally is there any way to remove my governor chip without replacing it? It tends to stick at 120, on track, of course.

Bryan, Austin, TX US 

Neither the engine or the driveline was designed, engineered or built to handle forced induction (positive displacement or turbocharging). There are a couple of reasons the addition of either will invalidate the warranty, only one of which has to do with the Clean Air Act. You are on your own with that sort of modification. I wish you luck.

You can safely redline the tach, if you mean going up to the redline. However I wouldn't be doing it with each and every upshift in the case of a Miata or any other car. But why do you have to in the first place? Once you get past peak power and torque, all rpm does is serve as an exceptionally weak testosterone substitute.

What you call the 'governor' chip is programming within the primary CPU. You can remove it, but the engine won't idle - or start - without it. Sort of like trying to use a computer without a mother board, or sending e-mail without a return address.

bwob

A weighty query

how fat are you in english stones

philip.exton, telford/shropshire/england

I don't know, but then I never cared much for the Stones. Or the Beatles.

bwob

A tip of the hat to Mister Two

What do you think of the new Toyota MR2 Spyder? Okay, so 500,000 haven't been sold, but how do you think it stacks up against the (say '00) Miata?

Aaron Pailthorp, Seattle, WA USA

I doubt that 500,000 will be sold, if even half that number. The MR2 has all the advantages as well as the actual problems served up by the car's mid-engined layout.

It's fun to drive, that's for certain. The steering has a nice bite, is well-weighted and there's even a nice - though not brilliant - exhaust note. The dry-road handling is good, initially with crisper turn-in than the Miata and is delightful in transient response. It feels quicker in a straight line as well (I'm basing that on gut feel and not numerical data).

The gearchange is really good for a mid-engined car, but still comes up second-best to the Miata's direct linkage. The program manager of the MR2 is a big promoter of the car's clutchless manual (which won't be offered in all markets) but I haven't had a chance to drive it yet. It's gotten some good write-ups in the Japanese press, saying it's as good as Alfa Romeo's similar Selespeed box.

Still, it's awfully hard to ignore the negatives. In the wet the car is a little spooky, serving to give the Miata what feels to be near front-drive surety by comparison. If people think a Miata gets spooky in the snow, they'll be likely to go white behind an MR2 tiller when the road is well coated.

The car also has absolutely no space utility whatsoever. Now the Miata has been broadly lambasted for a lack of trunk space, but alongside the MR's laughably tiny trunk (my wife called it the "secondary glove box"), the Miata suddenly looks like an amazingly versatile car.

The layout which 'makes' the MR2 also serves to limit it's appeal. It isn't at all unusual for Miata owners to be on their third - or sometimes fourth - car. Mid-engine cars (Ferraris notwithstanding since people are usually buying the badge and not the car) have historically had appalling secondary pick-up sales. The first mid-engine car these people purchased was usually the last one one they bought. This was one of the best arguments we made to Mazda management for having the Miata a front-engined, rear-drive car.

Styling is highly subjective, since there are some people who think the BMW Z3 (or maybe just the badge) is a good looker. As for what I think of the MR's exterior styling - and bear in mind I like anchovies on pizza - there's a colorful and suitable Australian expression I'll use;

"It's uglier than a hat full of broken arseholes."

Still, I'd have one long before a Z3 and as a second choice to a Miata it's hard to beat. After all, the interior's quite nice and that is where you spend most time with a car. But I wouldn't be sneaking glances of the car reflected in windows when I was stopped at a traffic light...

bwob

As leaves fall, snow worries rise

Am considering Miata, but in talking to the owner of an open front wheel sports car owner, he mentioned Miata a rear wheel drive car. So the question is how does the Miata or any other rear wheel drive car handle in our winter snow. And when it's not winter, what are the pluses and minuses of RWD vs FWD?

pat christian, Provo, Utah, USA

Huh? The owner of an "open front-wheel drive sports car"? A Capri owner? Couldn't be a DelSol - they're not open cars or sports cars.

For about seventy years, rear wheel drive didn't seem to bother people too much who even managed to populate inhabit snowy portions of the North American continent. Now people are paranoid about it, albeit for good reason relating to the primary safety device in a Miata.

Front wheel drive is not inherently safer than rear drive in poor conditions as much as it allows lazier, sloppier (dare I say less safe) driving. It's more forgiving of mistakes than rear-wheel-drive can be.

Good, really good, snow tires are a must. Studded if local laws allow. Also the Miata benefits from having a little extra weight in the trunk. Something in excess of 50 to 70 pounds would be a good place to start. An ideal form would be the vinyl-coated canvas bags of lead shot used in the film and photography business. Really good ones are made by an outfit called Mole-Richardson with built-in handles and a shape that makes them easy to locate - and stay put - in a Miata trunk.

Finally the single most important factor will be the driver. Drive like you would in a Sentra and you could be in big trouble. Apply the attention difficult conditions demand and you'll not only survive Winter but do even better behind the wheel come Springtime. The Miata will handle Winter snow in Utah (or anywhere else) only as well as the driver.

Major-league generalization time. Dry-weather benefits of front drive vis-à-vis rear-drive can include better straight-line stability as well as improved crosswind stability, lower manufacturing costs, lower weight and improved packaging with more useable interior space. Rear-drive advantages pale by comparison, highlighting potentially lower service costs and more balanced weight distribution resulting with potentially better vehicle dynamics. Mind you there are some horribly packaged front drive cars (the current Alfa Romeo GTV/Spider come quickly to mind) as well as decades of badly balanced rear-drivers. Hemicuda anyone?

bwob

Change for the better? Just ask Tyra

Have you actually driven a Miata with the 6-speed? Is this as good a transmission as the 5-speed in terms of smoothness, reliability? Does it add much to the Miata's fun quotient or is it mostly for bench racing? I'm currently driving a 92 with just under 200,000 miles and am getting the new car itch.

David, Kansas City, Missouri, USA

Yes I have and the answer is an completely unqualified yes and no. It's as reliable - if not a little more so with internals made by Toyota - as the original five-cogger. I don't think the shift linkage is as delightful as the five-speed and a couple of other wags seem to agree. Basically the quality of gearchanges from the six-speed a smidgen balkier and not quite as direct feeling as the basic Mazda five-speed. Mind you, this is a little like saying Elle MacPherson isn't as good looking as Tyra Banks. I wouldn't throw either out of the passenger seat in the highly unlikely event I am ever offered the opportunity.

bwob

Buy slowly, drive quicker

I bought a new Miata in Aug. I've been saving for past 5 yrs. I wasn't quite ready but decided to drive in to take a look. I let myself get talked into getting one that day. The salesman was ok, but I felt rushed and a bit manipulated. He gave me $500 off plus the standard $1,000 rebate. I was confused and didn't notice til I got home that I paid sticker price which was $20,000 -$1500. That should be $18,500 plus taxes, etc. total with tax, license was $26,000! Do I have any recourse. I won't take it there for repairs, unless they can do something which would be unlikely. I don't trust them. Can you give me any advice. I do love my Miata! I just feel sad that something so beautiful in my life seems tainted by this. Thanks

Craig Smith, SF/CA/usa

Well, now that the horse has bolted from the barn as it were, there's little advice I can offer. As for recourse, I am not au fait with what consumer protection statutes are on the books in California as regards car purchase, but if it bothers you that much you might want to inquire with the people at the Department of Consumer Affairs.

If you are ever feeling rushed when making any purchase, it's probably a good, if not great, idea to walk away. If the offer's genuine, it'll be there when you get back. If it isn't there are other people willing to sell you what you want.

In any event I wouldn't be taking the car back there for any kind of service. Even if it died in front of the dealer under warranty.

bwob

Bwob's world and welcome to it - WOOF!

I wonder if you're familiar with the works of the late humorist James Thurber. The style and tone of your "Ask Bob!" series is, to me at least, greatly reminiscent of Thurber's "The Pet Department." Perhaps you also draw cartoons of bloodhounds?

John Lawrence, Bloomington, Indiana USA

Being a fan of Thurber's I'm flattered, though I think I pale - greatly - by comparison. My cartooning of canines is limited to corgis, actually. However only republican (note the lower-case 'r'), not loyalist ones.

bwob

Terrified in Toronto

I'm have a serious problem with my 91 Miata where when I move off from a stop and am barely off the clutch and turning left, like at a light, I hear a VERY loud klunk. This klunk happens again when I shift into 2nd. It sounds like it is coming from the diff or the drive shaft. The klunking is so intense that it actually shakes the car. It is now at a point were I fear driving it at all. If the car continues going straight there is NO noise. This has been a progressive problem, the klunk was quite at first (always only on left turns) but within a month it is much worse. It is not a bearing problem. I know what those sound like and it is definitely not even close. Do you have any suggestions as to where I should look. U-joint? How can I tell if my diff is locking or non-locking? Any help would be appreciated.

Dwayne, Toronto, Ontario, Canada

The first place to look? Dwayne, if it were my car and if the problem is as serious as you believe (from 15578km it's nigh on impossible for me to determine the degree of seriousness, let alone what the specific problem is), the first place I'd be looking is at the cheerful countenance of a knowledgeable mechanic who can actually get their hands on the Miata to fix whatever's wrong with it.

bwob

Location, location, location

I have a 90 Miata. It has just about 70,000 miles and its sounds like the belts are going. Where is a good place to change them. Maybe they don't need to be changed and if not, can I put something on them to not make them be so loud, its not loud but you can hear them.

Alex, NYC

If it were my car, I'd be having them changed in the service department of John Newell Mazda. Now it's a long way from New York to Sydney, but I'm certain there's a similar facility near you.

If the belts are going bad, they should be replaced. However, if they don't need changing, you don't need to. Inasmuch as A) you can hear the noise they're making and B) it's your car, the call is yours. If you aren't sure, there are attentive and knowledgeable uniformed personnel at John Newell Mazda who are well skilled at determining such quandaries. I'd suspect that like facilities in the New York/New Jersey/Connecticut area might be similarly staffed. Good luck.

bwob

Can YOU read an eye chart from 9290 miles away?

My 91 Miata has a coolant leak which is originating near the top of the rear of the engine block. Cant quite make out the originating spot due to poor visibility to the area. Is this likely to be related to a connection to the heater, or is it more likely to be a gasket in the engine block itself? Any guesses or experiences in this area? Thanks in advance. All I can see is that it is dripping on the passenger side of the aft of the engine from a hose I believe to be related to the master cylinder. But where it is coming from to meet this hose, I cannot see.

Steve Smith, Atlanta, Ga

You can't see the leak? Believe me, from here in Australia the view's no better. The only guess I can make is that I guess you ought to see a trustworthy mechanic who can get their paws - and eyes - on the car.

bwob

'High pressure' sales with low pressure knowledge

I just bought the new Toyo Proxes T1-S 195/55R14. The guy at USA Tire who fitted them has kept the tire pressure at 44 lbs. When I inquired if it was not too high, he said that "that is the recommended tire pressure on the side wall of the tire."

What do you think? What is the optimum tire pressure for these tires for normal driving?

Eddy Damania, Davis, CA

I think you need to buy your tires elsewhere. The pressure information molded into the sidewall is the maximum allowable pressure, not the recommended pressure. Start at the manufacturer's suggestions in the owner's manual as a guideline and adjust things from there. Obviously in any event never more than 44psi/300kPa.

Regarding specific tire pressures, I strongly suggest that you do some experimentation on your own. My personal preference for final oversteer gives me pause at making exact recommendations. Unlike most Americans, I prefer going off the road tail-first.

bwob

Joke letter of the month, part 314

WHERE IS THE FUEL FILTER?

mike waldron, USA

Can't find it, eh? That's because it's RIGHT NEXT TO THE SHIFT AND CAPS LOCK KEYS.

bwob

Just what do these things do?

My 96 Miata is missing the 3 piece tubular rear suspension braces that bolt to the lower control arms, then forward to the body. And the third tube bolts between the lower control arms, across under the exhaust. I don't know why they are missing. Do I need them? I plan to occasionally run solo II but mostly I drive the car back and forth to work daily. I can't find anybody parting out a Miata around here to get these pieces from and the dealer wants a couple of hundred to order them. What do you recommend?

DAVID CREBO, East Peoria, IL. USA

Paying the couple of hundred and ordering them, then having them fitted.

bwob